Acceleration and deceleration control system



Sept. 7, 1937. G w, BAUGHMAN 2,092,366

ACCELERATION m) DECELERATION CONTROL SYSTEM Filed June 12, 1954 2 Sheets-Sheet 1 INVENTOR GEORGE W. BAUGHMAN BY ATTORNEY Sept. 7, 1937. G. w. BAUGHMAN ACCELERATION AND DECELERATION CONTROL SYSTEM 2 Sheets-Sheet 2 Filed June 12, 1934 INVENTOR GEORGE W. BAUGHMAN BY A ORN Patented S ept. l

. PATENT, OFFICE v v,

- ACCELI'IRATION' AND DECELERATION CON- I TROL SYSTEM .George .W. Baughman, Edgewood, Pas assignor to The Westinghouse Air Brake Company, Wilmerding, Par, a corporation of Pennsylvania Application June 12, 1934, Serial No. 730,231

' 14 Claims.

My invention relates tor-an acceleration and deceleration control system for railway vehicles and is particularly adapted 'for use on vehicles drivenby electric motors and retarded by electropneumaticbrake equipment.

In vehicles employing friction tyne brakes, it is well known that for a given braking pressure such brakes are less effective in retarding the motion of a vehicle at high speeds than at low speeds, because the coefiicientof friction between the rubbing parts is lower athigh speeds thanv at low speeds.- In order to bring a vehicle to a stop quickly it has been the usual practice-for an operator to apply the brakes with a high degree of braking pressure at high speeds, and, as the speed of the vehicle decreases, to cause the braking pressure to decrease atsuch a rate that the vehicle is brought to a stop quickly and smoothly without dangerous shock, or skidding of the wheels.- It has heretofore been proposed to pro-- vide retardation control apparatus to accomplish this varying of the braking pressure automatically in accordance with a preselected rate of re.- tardation. When a retardation rate controller is employed, the selected rate may be so great as to cause skidding of the wheels unless provision is made to limit the rate of retardation in such cases.

In the case of vehicles driven by electric motors it is usual to provide a notchlng controller that is governed by a master controller, and, when put into operation, automatically cuts out resistance from the motor circuit step by step until I the motor is brought up to full speed. In order to provide against too great overloading of the motor it is desirable to provide means for limiting the rate of operation of the notching controller during acceleration of the vehicle. It is desirable, therefore, in many installations, to provide a retardation and acceleration controller for limiting the rate of change in speed of the vehicle both during starting and stopping.

It is an object of my invention to provide an acceleration and deceleration control system for limiting the rate of increase,;and the rate of decrease, in the speed of the vehicle.

It is a more specific object of my invention to provide an acceleration and retardation control system in which the limiting rate of change inthe vehicle's speed is controlled by an electrical device responsive to the vehicle speed.

It is another object of my invention to provide an acceleration and retardation controller comprising an electrical relay energized with one polarity during acceleration of the vehicle and with the opposite polarity during deceleration of the vehicle, therelay completing circuits for controlling the acceleration or deceleration of the vehicle.

Other objects. and advantages of my invention will appear from the following description of a specific embodiment thereof when taken in conjunction with the accompanying drawings in which -'Flg. 1 is a diagrammatic view of circuits and apparatus comprising one preferred embodiment of the invention,

Fig. 2 illustrates a detail of the vehicle direcf tional switch, and

I Fig. 3 illustrates curves showing the operation of the acceleration and deceleration control relay and,

Figs. 4, 5, and 6 illustrate difierent circuit arrangements for controlling the energization of the acceleration and deceleration control relay.

Referring to Fig. 1 of the drawings, a motor circuit extends from an overhead conductor I through a trolley 2, contact member 3 of a circuit breaker 4, the driving motors 5 and 6, control resistor l, conductor 8, winding 9 of a current limiting relay ii to ground at H. The winding 9 actuates a core 13 of the current limiting relay ii that is mechanically connected to a core M by a stem l5, and which also extends downwardly andis connected to a contact member l6. Windings ll and iii are associated with the core M of the relay, the winding i'l acting to bias the core i4 downwardly against the upward movement pull of the core i3, and the winding l8 being so wound and connected as to have a differential. relation to the winding ll. A master controller I9 is provided for controlling the operation of the driving motors 5 and 6, and comprises an acceleration handle 21! for operating the contact members 22 and 23. When operated toward the right from the position shown in the dot and dash line the contact member 22 closes a circuit from a source of electric energy, through conductor 24, resistor 25, contact member 22,'conductor 2B, winding ill and conductor Tl to the source of energy. At the same time a circuit is completed from a source of energy through conductor 28, movable contact member 23 actuated by the acceleration handle 2i, segment 29, conductor it to the winding of the circuit breaker 4, energizing the circuit breaker and operating its contact member 3 into a circuit closing position to complete a circuit to the motors 5 and 6. Control circuits are also completed from the conducting segment 29 throu h conductor 32, one circuit extending along energy. A second control circuit extends fromtheconducting segment 29, through conductors 32 and 38, the winding of the operating magnet valve device 39, and conductor 4| to the source of energy. The above described operation of the acceleration handle 2| causes the winding I1 of the current limiting relay I I to be energized to an extent depending upon the amount of resistance 25 that is in circuit.therewith. The degree of energization of the windings I1 and I8 determines the downward pull on the core I4 that is required to be overcome by the upward pull of the core I3, energized by the winding9, in order to move the relay contact member I6 to a circuit interrupting position. The above traced circuits completed through the contact segment 29 cause the holding magnet valve 35 and the operating magnet valve device 39 to be actuated downwardly to their illustrated positions, thus causing operation of the acceleration controller 36.

The acceleration controller 36 also comprises a casing 42 extending between the magnet valve devices 35 and 39, and which defines a cylindrical chamber for containing the piston assembly 43 that is provided with a rack 44 upon the upper side thereof for engaging gear teeth on a pinion 45 which actuates the contact controlling member 46. The holding magnet valve device 35 comprises a casing enclosing a valve chamber 41 containing a double beat valve 48, from which valve chamber a port 49 leads into the left end of the piston chamber, a port 5| leads upwardly to an exhaust port 52 for connecting the left hand end of the piston cylinder with the atmosphere when the valve 41 is in its lower, or illustrated, position, and a port 53 leads downwardly and connects with an inlet chamber 54 that is connected by a pipe 55 to the reservoir 56. A spring 51 is provided in the inlet chamber 54 for biasing the valve 48 upwardly. The operating magnet valve device 39 comprises a casing enclosing an inlet valve chamber 58, containing the valve 59, and an outlet valve chamber 6| containing the valve 62. These two valve chambers are united by a port 63 from which branch port 64 leads into the left end of the piston chamber for supplying it with air under pressure from the inlet valve chamber 58, or for releasing air through the outlet valve chamber 6| and exhaust port 65. A spring 66 is provided in the inlet valve chamber for biasing the valves 59 and 62 upwardly against the force of the operating magnet. The contact arm 46 carried by the pinion 45 is adapted when moved in a clockwise direction from its illustrated position to consecutively engage the contact segments 61, 66, 69, 1| and 12 thus completing circuits through conductors 13, 14, 15, 16 and 11, and conductor 18 to shunt increasing portions of the starting resistor 1 from the motor circuit. When the motors 5 and 6 are not energized the contact arm 46 remains in engagement with a stop 19 as illustrated, and upon operation of the acceleration controller to increase the speed of the motors 5 and 6 a stop 8| prevents the contact arm 46 from passing beyond the contact segment 12.

A brake equipment is provided of the well known fluid pressure type and comprises a brake valve 82 operated by a handle 83 for connecting the reservoir 56 through pipes 84, 85, and the brake cylinder pipe 86 to the brake cylinder 81 to apply the brakes, and for releasing air under pressure from the brake cylinder 81 through the brake valve 82 to the atmosphere in a well known manner to release the brakes. An application magnet valve device 88 is located between the pipes 85 and 86 and is normally maintained in its open or illustrated position to permit free flow of air between the brake valve 82 and the brake cylinder 81. A releasemagnet valve device 88 is provided and is normally maintained in its closed position in order to maintain pressurewithin the brake cylinder 81. The application magnet valve device 88 and the release magnet valve device 89 are controlled by operation of an acceleration and deceleration control relay 9| one 'part of which is energized from an axle driven generator 92 that is operated in accordance with the speed of cation valve 98 that is normally biased to its upper or open position by a spring 99 in the inlet chamber 95. An outlet port IOI communicates from the valve chamber 91 with the brake cylinder pipe 86. The release magnet valve device 89 comprises a casing I02 having an inlet port I03 connecting the brake cylinder pipe 86 with a valve chamber I04 containing a valve I05 normally biased to its upper or closed position by a spring I06 to close a port I01 communicating between the valve chamber I04 and outlet chamber I09 to exhaust port I08.

The acceleration and deceleration control relay 9| is provided with a field core structure III that is energized by windings H2 and H3, that are connected in series in a circuit represented by conductors H4 and IIS and energized from a suitable source of direct current energy. An armature core 6 is pivotally supported at II1 between the pole faces of the U-shaped field core I I I, and is energized by an armature winding I I8 that is connected by conductors H9 and I2I to the secondary winding I22 of a transformer I20. A primary winding I23 of the transformer I20 is energized from the armature winding I24 of an axle driven generator 92 that is operated in accordance with the speed of the vehicle. The generator field winding I 25 is energized from conductors I26 and I21 that are respectively connected to the contact plates I28 and I29 of the vehicle directional switch 93. In the illustrated position of the switch 93 the contact plates I28 and I 29 are respectivelyin engagement with contact members I3I and I32, that are connected by conductors I33 and I34, respectively, to a suitable source of direct current energy. In the second operative position of the vehicle directional switch 93 the switch plates I28 and I29 are in contact, respectively, with contact members I35 and I36 thus reversing the direction of energization of the field winding I25 of the axle driven generator 92.

The vehicle directional switch 93 is actuated to one of its two operative positions by a U- shaped magnet I31 that is pivotally supported at I38, the open end of the U-shaped core being positioned upon opposite sides of a metallic flange ing I23 of the transformer in Fig. 1.

I39 of magnetizable material carried by a shaft I4I, as best shown'in Fig. 2. The magnetic drag existing between the flange I39 and the U-shaped armature I31 causes the armature to be actuated in the one or the other direction in accordance with the direction of rotation of the shaft |4|, which may be an axle of the vehicle or any shaft driven in accordance with speed of the vehicle. i

The armature core ||6 of the relay 9| carries an arm I42, that is normally biased to its cen tral or illustrated position by the springs I43 and I44, and at the outer end of which a contact member I45 is carried that is adapted to be and conductor I54 to thesource of energy, thus I energizing the winding I8 to partially neutralize the efiect of the winding I|. Upon a further movement of the contact member I45 toward the left engageinentls made between contact members I45 and I41 thus completing a circuit through the coil 18, in shunt relation to the resistor I52, to further energize the winding I8 and more nearly neutralize the effect of the winding ||,'thus permitting the current limiting relay II to move its contact member I6 upwardly upon a smaller current flow through the winding 9. I

If the contact member I45 is actuated toward the right until it engages contact member I48 a circuit is completed from the conductor I5I through contact members I45 and I48, conductor I55, and the winding of the application magnet valve device 88 to ground. The valve 98 is accordingly actuated downwardly to close the port 98 and interrupt the flow of air through the brake valve 82 to the brake cylinder 81, thus preventing further increase in pressure in the brake cylinder 82. If the contact member I45 moves further toward the right it will engage the contact member I49 .and complete a circuit through the conductor I56 and the winding of rent through the armature winding I24. of the acceleration generator 92 and the primary wind- From the point I5! to the point I58 on the curve A the vehicle is accelerating at a uniform rate as represented by the straight line joining these two points. The direct current through the primary winding I23 of the transformer I20 will accordingly build up as shown by the curve A. The current induced in the secondary winding I22 of the transformer I20 will build up to a value X,

as shown by the curve B, at which value the speed of thevdiicle remains constant as does also the direct current through the primary winding I23 of thetransformer I20. Since the current in the secondary winding I22 of the transformer is dependent upon the rate of 7 change of the primary current, the current will drop to zero value as represented by the downward sweep of the curve B and remain at zero until the rate of speed of the vehicle again' curveA the vehicle is represented as decelerating at a uniform rate as indicated by the straight line between these two points. A current will accordingly build up in the secondary winding I22 of the transformer I20 as shown by the curve C to a value. Y, dependent upon the rate .of deceleration of the vehicle, and remain at that value so long as the rate of deceleration remains constant. The curve C is similar in character to the curve B except that it is on the other side of the zero line and represents the flow of current through the secondary winding I22 of the transformer and the winding I I8 of the relay 9| in the opposite direction.

During the acceleration period of the vehicle,- current flows through the winding II8, as represented by curve B, causing a torque on the armacurrent value and which actuates it in a. counterclockwise-direction to cause engagement of the contact I45 with the contact members |48and I41 to close the circuit above traced. As soon as the vehicle reaches a constant speed the energization of the relay winding 8 ceases and the relay armature H6 and the contact member I45 are actuated by the springs I43 and I44 to their mid, or illustrated, positions. During the period of deceleration represented by the curve C, current will flow through thewinding N8 of the relay 9| in a direction to cause movement of the core II6, andcontact member I45, in a clockwise direction to close circuits through contact members I48, and I49 as above traced. The current values through the relay winding 8 represented by theordinates X and Y of the curves B and C,

respectively, will be dependent upon the rate of acceleration or deceleration of the vehicle.

Since the generator 92 is driven from the axle of the vehicle a, reversal in the direction of operation of the vehicle will cause a reversal in the polarity or direction of current through the generator armature, unless the direction of energization of the field winding I25 is reversed upon reversal of direction of operation of the vehicle. In order to provide against such reversal of polarity of the generator 92, and to insure that ,the relay 9| will always operate in a counterclockwise .direction during acceleration of the vehicle, and in a clockwise direction during deceleration of the vehicle, the vehicle directional switch 93 is provided for automatically reversing the direction of energization of the generator field winding I25 upon a reversal in the direction of operation of the vehicle. a

To summarize the operation of the acceleration and deceleration system as a whole, if the'operator wishes to start the vehicle the acceleration handle 2| ismoved toward the right to close a circuit through the contact member 23 and contact segment 29 for operatingthe circuit breaker 4 to-itscircuit closing position, thus completing a circuit through the motors 5 and 6, and, at the same time, completinga circuit through the winding of the operatingmagnet valve device 39 and the holding magnet valve device 35 o! the acceleration controller 36. The valves of the devices 35 and 39 are accordingly operated downwardly, the device 35 venting that portion of the piston chamber to the left of the piston assembly 43 through ports 49, 5| and 52 to the at-' mosphere. The operating magnet valve device 39 cuts ofi communication between the piston chamber to the right of the piston assembly 43 and the atmosphere through exhaust port 65, and admits air under pressure from the pipe through valve chamber 58 and port 64 to operate the piston assembly 43 toward the left. The pinion 45 and contact arm 46 are accordingly moved in a clockwise direction to cut successive portions of the resistor 41 from the motor circuit and accelerate the motors 5 and 6. The motor current circuit includes the winding 9 of the current limiting relay II, which, upon the flow of a predetermined current therethrough, operates upwardly to interrupt a circuit through its contact member I6 and deenergizes the winding of the holding magnet valve device 35. The valve 48 is thus forced upwardly by the spring 51, closing the passage through the exhaust port from the left of the piston assembly 43, and supplying air to this portion of the piston chamber through pipe 55, valve chamber 41 and port 49, thus preventing further operation of the arm 46 in' a clockwise direction until the holding magnet valve device 35 is again energized. The current through the motor circuit and the winding 9 of the current limiting relay required to operate the relay to deenergize the holding magnet 35 is determined by the energization of the relay winding II which is greater, the further the acceleration handle 2| is moved toward the right, thus cutting out of the circuit a greaterportion of the resistor 25.

During acceleration of the vehicle the acceleration and deceleration control relay 9| is actuated in a, counter-clockwise direction as above explained, and, should the rate of acceleration of the vehicle become sufiicient, the contact member I45 would engage the. contact member I46 thus partially energizing the winding I8 and correspondingly neutralizing the effect of the winding H to permit the current limiting relay II to open with a smaller amount of current through the winding 9. This causes operation of the current limiting relay II to permit a smaller maximum current through the motors 5 and 6. Should this maximum motor current cause a rate of acceleration that is still larger than that determined by the relay 9|, the contact member I45 thereof will be moved further toward the left, causing engagement between it and the contact member I41 to further increase the energization of the differential winding III of the relay I I to more completely neutralize the efiect of the winding I1, and to establish a new setting for the current limiting relay whereby it will open when a smaller current flows through the coil 9.

Unless otherwise operated by the control relay 9|, the application magnet valve device 88 remains in its open or illustrated position, and the release magnet valve device 89 remains in its illustrated or closed position. The operator may, accordingly, move the handle 83 of the brake valve 82 to supply fluid under pressure to the brake cylinder 81 through the open application valve device 88, or to vent air under pressure from the brake cylinder through the valve device in the usual way, the pressure being maintained in the brake cylinder by the release magnet valve device 89 in its closed position. I! the rate of deceleration of the vehicle is greater than that permitted by the relay 9| the contact member I45 will be moved in a clockwise direction to close the application magnet valve device 88 and prevent further increase in pressure in the brake cylinder, and, upon a further operation in a clockwise direction, to close a circuit to the winding of the release magnet valve device 89 and cause it to operate to vent airunder pressure from the brake cylinder 81 to the atmosphere, thus releasing the brake, until the rate of deceleration of the vehicle has been reduced to a value suflicient to cause separation of the contact members I45 and I49.

Fig. 4 illustrates a second preferred embodiment of means for maintaining the acceleration and deceleration relay 9| energized in accordance with the rate of acceleration and deceleration of the vehicle. The transformer I20 illustrated in Fig. 1 is omitted from the circuit shown in Fig. 4 and a condenser I62 is connected in series circuit relation between the armature winding I24 of the axle driven generator 92 and the winding II8of the relay 9|. In this embodiment of the invention, while the speed of the vehicle increases between points I51 and I58 on the curve A shown in Fig. 3, the speed and voltage of the generator 92 correspondingly increases causing a charging current to flow from the generator to the condenser I62 in accordance with the curve B of Fig. 3. A counter-electromotive force is built up on the condenser I62 that is equal and opposite to the electro-motive force from the armature winding I24 of the generator 92. While the vehicle is operating at constant speed, as represented by the portion of the curve A between points I58 and I59, the voltage of the generator 92 and of the condenser I62 remains constant and there is no exchange of current between them. Energy remains stored in the condenser I62 as a result of the current shown by the curve B from the generator to the condenser. During deceleration of the vehicle this stored energy causes a discharging current to fiow from the condenser I62 to the generator 92, which will be in the opposite direction to the charging current as represented by the curve C in Fig. 3.

The acceleration and deceleration control relay 9| illustrated in Figs. 5 and 6 corresponds to the relay illustrated in Figs. 1 and 4 and may be energized by means of the mechanisms illustrated in either of these figures. In Fig. 5 an adjustable rheostat I63 is provided in series with the relaywinding II8 for adjusting the degree of acceleration or deceleration that it is desired to permit. In Fig. 6 an adjustable rheostat I64 is illustrated in shunt relation to the relay winding 8 and a resistor I65 is also illustrated in series relation to the winding II8 which may be employed if desired. By the use of such resistors the relay 9| may be adjusted to permit any desired degree of acceleration or deceleration.

While I have illustrated and described certain preferred embodiments of my invention, it will be apparent that many modifications thereof will occur to those skilled in the art within the spirit of my invention, and I do not wish .to be limited otherwise than by the scope of the appended claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a brake equipment for vehicles, the combination with a fluid pressure braking means, of means for limitingthe deceleration of said vehicle comprising an application magnet valve, a release magnet valve, electro-rsponsive control means therefor, and means for energizing said electro-responsive control means in accordance with the rate of deceleration of said vehicle.

Cir

2. In a brake equipment for vehicles, the combination with a fiuid pressure braking means, of means forlimiting 'the deceleration of said vehicle comprising an electro-responsive control means, a direct current generator operated'in accordance with the speed of the vehicle, and means connected between said generator and said electro-responsive control means for effecting a current supply thereto that is a measure of the rate of change in the speed of the generator.

3. In a brake equipment for vehicles, the combination with a fluid pressure brake, of means for limiting the deceleration of said vehicles comprising an electro-responsive control means, a direct current generator operated in accordance with the speed of the vehicle, means connected between said generator and said electro-responsive control means for effecting a current supply thereto that is a measure of the rate of change in the speed of the generator, and means for automatically maintaining the polarity of the generator independently of the direction of operation of the vehicle. 4. In a brake equipment for vehicles, the combination with a fiuid pressure braking means, of means for limiting the deceleration of said vehicle comprising an electro-responsive control means, a direct current generator operated in accordance with the speed of the vehicle, means connected between said generator and said electro-responsive control means for effecting a current supply .thereto that is a measure of the rate of change in thespeed of the generator, and means for adjusting the sensitivity of the electro-responsive control means to change the permitted rate of deceleration of the vehicle.

5. In a brake equipment for vehicles, in combination, means for applying a braking force to the vehicle, and means for controlling the braking force applied thereto comprising an electroresponsive control means, a direct current generator driven in accordance with the speed of the vehicle for governing the operation of said electroresponsive control means and arranged to deliver a voltage that is a measure of the speed thereof, means connected between said generator and said electroresponsive control means for effecting a current supply to said electroresponsive control means that is a measure of the direction and rate of speed change of the generator, and means for automatically maintaining the polarity of the generator independently of the direction of operation of the vehicle.

6. In a brake equipment for vehicles, in combination, means for applying a braking force to the vehicle, means for limiting the braking force applied to the vehicle, electroresponsive controlmeans for controlling the operation of said limiting means, a direct current generator driven in accordance with the speed of the vehicle for governing the operation of said electroresponsive control means and arranged to deliver a voltage that is a measure of the speed thereof, means connected between said generator and said electroresponsive control means for effecting a current supply to said electroresponsive control means that is a measure of the direction and rate of speed change of the generator, and means for 7. In a brake equipment for vehicles, in com- 7 bination,- means for applying a braking force to .-the vehicle, means for limiting the braking force applied to the vehicle, electroresponsive control means for controlling the operation of said limiting means, a direct current generator driven in accordance with the speed of the vehicle for governing the operation of said electroresponsive control means and arranged to deliver a voltage that is a measure of the speed thereof, and means connected between said generator and said electroresponsive control means for eifecting a current supply to said electroresponsive control means that is a measure of the direction and rate of speed change of the generator.

8. In a brake equipment for vehicles, in combination, means for applying a braking force to the vehicle, means for limiting the braking force applied to the vehicle, electroresponsive control means for controlling the operation of said limiting means, a direct current generator driven in accordance with the speed of the vehicle for governing the operation of said electroresponsive means and arranged to deliver a'voltage that is i i 9. Ina'brake equipment for vehicles, in combination, means for applying a braking force to.

the vehicle, means for limiting the braking force applied to the vehicle, electroresponsive control means for controlling the operation of said limiting means, a direct current generator driven in accordance with the speed of the vehicle for governing the operation of said electroresponsive means and arranged to deliver a voltage that is a measure of the speed thereof, and a transformer having its primary winding connected in circuit with said generator and its secondary winding connected in circuit with the winding of said electroresponsive control means. I

10. In a brake equipment for vehicles, in combination, means for applying a braking force to the vehicle, means for limiting the braking force applied to the vehicle, electroresponsive control means for controlling the operation of said limiting means, a generator driven in accordance with the direction and speed of the vehicle, means for controlling the energization of said electroresponsive means from said generator whereby the direction of current flow therebetween is a measure of the direction of speed change of said vehicle and the degree of energization is a measure of the amount of such acceleration or deceleration, and means for maintaining the polarity of the generator in the same direction irrespective of the direction of operation of the vehicle.

11. In a brake equipment for vehicles, in combination, means for applying a braking force to the vehicle, means for limiting the braking force applied to the vehicle, a contact making electrically controlled torque relay having a magnetic circuit comprising a polarized field portion and an armature portion, a winding for energizing said armature portion, a direct current generator driven in accordance with the speed of the vehicle for governing the operation of said electroresponsive means and arranged to deliver a voltage that is a measure of the speed thereof, and a transformer having its primary winding connected in \circuit with said generator and its secondary winding in circuit with the armature winding said electrically controlled torque relay.

12. In a brake equipment for vehicles, in combination, a brake cylinder, means for controlling 5, the rate of deceleration of said vehicle comprising magnet valve devices for controlling the degree of fluid pressure in said brake cylinder, 9. contact making electrically controlled torque relay for controlling said magnet valve devices and hav- 10 mg a magnetic circuit comprising a polarized field portion and an armature portion, a winding for energizing said armature portion, a direct current generator operated in accordance with the speed of the vehicle, means connected be- 5 tween said generator and said electrically controlled relay ior eflecting a current supply thereto that is a measure of the rate of change in the speed of the generator, and means for adjusting the sensitivity of the relay to change the per- 20 mitted rate of deceleration of the vehicle.

13. In a brake equipment for vehicles, in combination, a brake cylinder, manually operated means for effecting the supply of fluid under pressure to said brake cylinder, means for con- 25 trolling the pressure in said brake cylinder comprising magnet valve devices and a contact making electrically controlled torque relay having a magnetic circuit comprising a, polarized field portion and an armature portion, a winding for 30 energizing said armature portion, a generator driven in accordance with the direction and speed of the vehicle, means for controlling the energization of the armature winding of said electrically controlled torque relay from said 35 generator whereby the direction of current flow therebetween is a measure of the direction of speed change of said vehicle and the degree of energization is a measure of the amount of such deceleration, and means for maintaining the polarity oi the generator in the same direction irrespective of the direction of operation of the vehicle.

14. In a brake equipment for vehicles, in combination, a brake cylinder, manually operable means for eflecting the supply of fluid under pressure to said brake cylinder, an application magnet valve device for limiting the supply oi! fluid under pressure to said brake cylinder, a release magnet valve device ior releasing fluid under'pressure from said brake cylinder, 2, contact making electrically controlled torque relay for controlling said magnet valve devices having a magnetic circuit comprising a field portion and an armature portion, a winding tor energizing one of said portions, a generator driven in accordance with the direction and speed of the vehicle, means for controlling the energization oi! said torque relay from said generator whereby the direction of current flow therebetween is a measure of the direction of speed change of the vehicle, and the degree of energization is a measure of the amount of such acceleration or deceleration, contact making means controlled by said relay for controlling the operation of said magnet valve devices when the relay is moved in one direction from a neutral position, and control circuits for controlling the rate of acceleration (if the vehicle when the relay is moved in the opposite direction from a neutral position, and means for controlling the flow of energy from said generator to the winding of said relay for actuating it in the one direction or in the other direction in accordance with the acceleration or deceleration of, the vehicle.

GEORGE W. BAUGHMAN. 

